AUTHOR=Shen Yan , Chen Yuan-Zhi , Lou Yi-Han , Zhang Chuan-Xi 

TITLE=Vitellogenin and Vitellogenin-Like Genes in the Brown Planthopper

JOURNAL=Frontiers in Physiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2019.01181

DOI=10.3389/fphys.2019.01181

ISSN=1664-042X

ABSTRACT=<p>Vitellogenin (Vg) is precursor of vitellin. Here, we identified a <italic>Vg</italic> (<italic>NlVg</italic>) and two <italic>Vg</italic>-likes (<italic>NlVg</italic>-like1 and <italic>NlVg</italic>-like2) in the brown planthopper, <italic>Nilaparvata lugens</italic>. Phylogenetic analyses showed that NlVg-like1 and NlVg-like2 are not clustered with the conventional insect Vgs associated with vitellogenesis. Temporo-spatial expression analyses showed that the <italic>NlVg</italic> and <italic>NlVg</italic>-like2 transcript levels increased significantly 24 h after emergence and were primarily expressed in female adults. However, <italic>NlVg</italic>-like1 was expressed during all stages, and in both genders. Tissue-specific analyses showed that all three genes were most highly expressed in the fat body. The injection of double-stranded RNA targeting <italic>NlVg</italic> showed that <italic>NlVg</italic> is essential not only for oocyte development but also for nymph development. The knockdown of <italic>NlVg</italic>-like1 in female adults resulted in failure to hatch or death before eggshell emergence in 18% of offspring embryos, suggesting that <italic>NlVg</italic>-like1 plays an important role during late embryogenesis. Approximately 65% of eggs laid by females that were treated with double-stranded RNA targeting <italic>NlVg</italic>-like2 failed to hatch, indicating that <italic>NlVg</italic>-like2 plays a role in nutrition absorption during oocyte, or embryonic development. Our results illustrate the structural and functional differences among the <italic>Vg</italic> and <italic>Vg</italic>-like genes and provide potential targets for RNA-interference-based insect pest management strategies.</p>